Explosives in explosive devices have been used for general industrial applications, for example as dynamite, and also for military applications such as chemical weapons (e.g., shell, bomb, land and naval mines). Considering the fume after explosion, an oxidizer or the like is added to the explosives such as dynamite for use in general industrial applications to make the oxygen balance thereof positive or to prevent it from becoming drastically too negative. On the other hand, explosives for use in military applications such as chemical weapon have a negative oxygen balance, to make the most of their respective destructive forces. In addition, chemical weapons contain a chemical agent hazardous to the body such as sulfur mustard or lewisite, together with explosives.
A method of decomposing an explosive completely by blasting it in a pretreatment phase has been known as a method of processing a chemical weapon containing an explosive (see Patent Document 1). The blasting method is used for processing chemical weapons that cause significant corrosion and damage and those having a complicated structure that are difficult to disassemble, and blasting is commonly performed while the chemical weapon is enclosed in a pressure vessel. Chemical weapons still containing a chemical agent are blasted by the method.
A method of decomposing an explosive completely by blasting it after the chemical weapon is disassembled and the chemical agent is removed in a pretreatment phase is also known as a method of processing chemical weapons containing explosive (see Patent Document 2). The blasting method is used for processing of a chemical weapon still retaining its original external shape, and the burster unit disassembled from the chemical weapon is blasted as it is enclosed in a pressure vessel. Although most of the chemical agent is removed in disassembling operation, the burster unit still having some solidified chemical agent adhered thereto by aging is blasted by the method.
In the two blasting methods described above, blasting is said to be performed favorably in a tightly sealed pressure vessel under vacuum, for the following reasons:    (1) It is possible to prevent leakage of the chemical agent contained in the chemical weapon to outside, because it is possible to keep the pressure in the pressure vessel lower (negative) than atmospheric pressure before blasting as well as after blasting; and    (2) It is possible to reduce adverse effects on environment including the noise and vibration by blasting drastically.
Patent Document 1: Japanese Unexamined Patent Publication No. 7-208899
Patent Document 2: Japanese Unexamined Patent Publication No. 2002-39699